Review Article

Oxidative Stress and DNA Methylation in Prostate Cancer

Figure 1

Effect of oxidative stress on DNA methylation. Antioxidant enzymes, for example, GSTP1 or antioxidants scavenge the ROS in normal cells. (A) depicts hypomethylation of DNA by ROS. 1, 2, and 3 represent DNA base modification, DNA deletion, and chromosomal breakage, respectively, all of which interfere DNMT activity. (B) Under increased ROS concentrations; the MBPs, HDAC and DNMT complex methylate the CpG sites resulting in reduced GSTP1 expression. Further increase in ROS results in complete loss of GSTP1 (key) by hypermethylation. (C) and (D) represent ROS-mediated oxidation of guanine to 8-Oxy guanine and cytosine to hydroxymethyl cytosine, respectively. Both modifications interfere with MBP-mediated methylation (details are given in the text).
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